The Effect of Phenylephrine and Ephedrine on Microvascular Blood Flow
Status:
Unknown status
Trial end date:
2015-08-01
Target enrollment:
Participant gender:
Summary
During operations to treat abdominal problems the blood pressure can fall, resulting in falls
in blood flow to the vital organs. This fall can be treated by the administration of drugs
that cause constriction of blood vessels. Although these drugs correct falls in blood
pressure, it is unclear what effect they have on blood flow from the heart and to the vital
organs.
In this study of healthy volunteers we aim to better understand the changes in blood flow in
both small and large vessels that occur in response to administration of these drugs. To do
this we will use two different techniques of ultrasound imaging. A narrow (4-5mm) ultrasound
probe will be inserted into the oesophagus via a nostril to measure blood flow in a major
blood vessel. A second probe will rest on the abdomen and will record changes in blood flow
in small vessels of the liver. Two drugs which raise the blood pressure via different
mechanisms will be administered and the changes in flow from the heart and to vital organs
will be measured and compared.